Part 82 · Module 15: Runtime and InfrastructureModule 15: Runtime and Infrastructure1 min read·13 Oct 2026What you need firstModule 1: the returns_desk/ package and tests with pytest.Module 3: the eight tools in returns_desk/tools.py, TOOL_DEFS and call.Module 5: the agent loop and its step, time and cost limits.Module 8: checkpoints, resumable runs and idempotency keys.Basic HTTP: a request, a response, a status code.